AQUALITY®

is a micro- or ultrafiltration system for treating raw water and producing high quality water, free of suspended solids, colloidal material and bacteria. The AQUALITY® filtrate is typically characterized by a complete removal of suspended solids, a log 5 reduction (>99.999%) of bacteria such as Cryptosporidium, a filtrate turbidity <0.1 NTU (no matter what the feedwater turbidity is) and an SDI (Silt Density Index) < 2.

This means that the MF or UF-filtrate is ready for reuse in potable applications or is perfectly pre-conditioned to serve as feedwater for a reverse osmosis installation. AQUALITY® processes are generally discontinuous dead-end filtration processes. Contrary to the EXSEL® processes that use crossflow filtration to keep the membranes clean AQUALITY® processes are characterized by a dead-end filtration cycle which is being alternated with a periodic backwash cycle.

The membranes used for this application are hollow fibre membranes and a differentiation can be made in the filtration mode which can be 'inside-out' or 'outside-in'. Waterleau developed a special range of proprietary membrane cleaning agents.

Typical applications

Municipal drinking water production

Industrial process water make-up. Feedwater sources for potable water or process water can be of any kind, such as

Turbid ground water

Surface water

Seawater

Bio-effluent

EXSEL®

While AQUALITY® processes will retain suspended solids, EXSEL® processes such as nanofiltration and reverse osmosis will retain dissolved solids.

The EXSEL® process uses a pump and a semi-permeable membrane. The pump provides the driving force for the separation, while the semi-permeable membrane passes water in preference to the solute that is dissolved in the water. Thus the majority of the solute is left behind to form a more concentrated stream. Since feed- and concentrate stream move tangentially to the membrane, the filtration principle is called crossflow filtration.

The process of reverse osmosis is not the same as filtration. Filtration is the removal of particles by size exclusion, while in reverse osmosis such physical holes may not exist. It is more likely that water is able to diffuse through the membrane polymer by bonding between segments of the polymer's chemical structure.

Recent improvements in semi-permeable membranes used have caused a dramatic improvement in the economics of reverse osmosis. Different setups and different membrane types can be used in order to offer the best solution for a specific application.

Waterleau can offer you solutions for seawater desalination, landfill leachate treatment, bio-effluent reuse and potable water production from surface water.

Typical applications

The most common application of EXSEL® is the desalination of water. Also the industry makes heavy use of this application of RO for producing highly purified process water, and for treating industrial wastewater. The RO process is also used to make potable (drinkable) water by desalination of brackish water or seawater.

Seawater desalination

Production of highly purified process water or potable water from any water source